Kabushiki Kaisha Toshiba

Gen Ohshima

Yoko Masuo

Motohiro Matsuyama

According to one embodiment, a semiconductor memory apparatus includes a memory and a speed control unit. The speed control unit calculates a time-varying behavior of a permissible value of an accumulated amount of data written in the non-volatile semiconductor memory, where, after a start of a guaranteed period, data is written in the memory at a constant write speed so that the permissible value at an end time of the guaranteed period is equal to a sum of a first capacity and a second capacity. The first capacity is an accumulated amount of data written in the memory. The second capacity is an accumulated amount of data which is writable in the memory in a remaining time of the guaranteed period based on remaining rewritable times of existing blocks. The speed control unit controls a transmission speed of data from a host based on the permissible value.

Semiconductor memory apparatus, data transmission device, and recording method

According to one embodiment, a memory system includes a non-volatile memory and a memory controller that controls the non-volatile memory. The non-volatile memory includes a memory cell array and an access control unit. The access control unit performs a program operation for changing threshold voltages of memory cells and a read operation for reading data from the memory cells. The memory controller includes a read/write control unit having a first program parameter set and a second program parameter set. The read/write control unit causes the access control unit to perform a program operation based on the first program parameter set, and when a predetermined condition is satisfied, performs switching from the first program parameter set to the second program parameter set and causes the access control unit to perform a program operation based on the second program parameter set.

Memory system and memory controller

According to one embodiment, a memory system includes a NAND-type flash memory and a memory controller. A comparison module of the memory controller compares a first threshold voltage distribution of a first memory area with a second threshold voltage distribution of the first memory area acquired earlier than the first threshold voltage distribution, if an error is detected in data read from the first memory area. An error factor determination module of the memory controller determines a cause of the error based on the comparison result, and inhibits a data move operation of moving data of the first memory area to the second memory area based on the determination result.

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Tokyo, Japan

Gen Ohshima